(Pwn2Own) Cisco RV340 upload.cgi sessionid Improper Input Validation Authentication Bypass Vulnerability

This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of Cisco RV340 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of the sessionid parameter provided to the upload.cgi endpoint. The issue results from the lack of proper validation of the user-supplied sessionid cookie. An attacker can leverage this vulnerability to bypass authentication on the system.